Ink jet printing can be performed using an ink jet print head that includes multiple nozzles. Ink is introduced into the ink jet printhead and, when activated, the nozzles eject droplets of ink to form an image on a substrate. The printhead can include fluid delivery systems with deformable actuators to eject fluid from a pumping chamber of the printhead. The actuators can be deformed to change a volume of a pumping chamber. As the actuators are driven, changes in the volume can cause fluid to be ejected from the fluid delivery system. The actuators, when deformed, can experience material stresses.